There is a Polish saying that goes : "If they kick you out the door, you should come back through the window."

Brian Acton, who started the instant messenger company WhatsApp in 2009, may have just proven that saying to be true. Acton started the company, with a partner, after his own job applications to Facebook and Twitter had both been rejected. Yesterday, the pair sold WhatsApp to Facebook for $19 billion in cash and stock.

The sale is a record-beating price – more by far than Microsoft's acquisition of Skype (a modest $8.5 billion).

Jim Goetz of American venture capital firm Sequoia, which was chosen by Brian and Jan as their business partner, said: “If you were in Spain of Brazil, most of the population there is interacting with WhatsApp multiple times a day,” and “is likely to touch a billion or more in the not-too-distant future.”

Jan Koum also pointed out: "Almost five years ago we started WhatsApp with a simple mission: building a cool product used globally by everybody. Nothing else mattered to us."